Fix btcsuite#79 by adding a new node JSON-RPC command

* Gives node operators full control of peer connectivity * RPC adds ability to disconnect all matching non-persistent peers, remove persistent peers, and connect to peers making them either temporary or persistent.
davecgh · Apr 15, 2015 · 65b044e · 65b044e
1 parent 6c12445
commit 65b044e
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Showing 6 changed files with 383 additions and 25 deletions.
diff --git a/btcjson/v2/btcjson/btcdextcmds.go b/btcjson/v2/btcjson/btcdextcmds.go
@@ -7,6 +7,42 @@
 
 package btcjson
 
+// NodeSubCmd defines the type used in the addnode JSON-RPC command for the
+// sub command field.
+type NodeSubCmd string
+
+const (
+	// NConnect indicates the specified host that should be connected to.
+	NConnect NodeSubCmd = "connect"
+
+	// NRemove indicates the specified peer that should be removed as a
+	// persistent peer.
+	NRemove NodeSubCmd = "remove"
+
+	// NDisconnect indicates the specified peer should be disonnected.
+	NDisconnect NodeSubCmd = "disconnect"
+)
+
+// NodeCmd defines the dropnode JSON-RPC command.
+type NodeCmd struct {
+	SubCmd        NodeSubCmd `jsonrpcusage:"\"connect|remove|disconnect\""`
+	Target        string
+	ConnectSubCmd *string `jsonrpcusage:"\"perm|temp\""`
+}
+
+// NewNodeCmd returns a new instance which can be used to issue a `node`
+// JSON-RPC command.
+//
+// The parameters which are pointers indicate they are optional.  Passing nil
+// for optional parameters will use the default value.
+func NewNodeCmd(subCmd NodeSubCmd, target string, connectSubCmd *string) *NodeCmd {
+	return &NodeCmd{
+		SubCmd:        subCmd,
+		Target:        target,
+		ConnectSubCmd: connectSubCmd,
+	}
+}
+
 // DebugLevelCmd defines the debuglevel JSON-RPC command.  This command is not a
 // standard Bitcoin command.  It is an extension for btcd.
 type DebugLevelCmd struct {
@@ -45,6 +81,7 @@ func init() {
 	flags := UsageFlag(0)
 
 	MustRegisterCmd("debuglevel", (*DebugLevelCmd)(nil), flags)
+	MustRegisterCmd("node", (*NodeCmd)(nil), flags)
 	MustRegisterCmd("getbestblock", (*GetBestBlockCmd)(nil), flags)
 	MustRegisterCmd("getcurrentnet", (*GetCurrentNetCmd)(nil), flags)
 }
diff --git a/btcjson/v2/btcjson/btcdextcmds_test.go b/btcjson/v2/btcjson/btcdextcmds_test.go
@@ -42,6 +42,64 @@ func TestBtcdExtCmds(t *testing.T) {
 				LevelSpec: "trace",
 			},
 		},
+		{
+			name: "node",
+			newCmd: func() (interface{}, error) {
+				return btcjson.NewCmd("node", btcjson.NRemove, "1.1.1.1")
+			},
+			staticCmd: func() interface{} {
+				return btcjson.NewNodeCmd("remove", "1.1.1.1", nil)
+			},
+			marshalled: `{"jsonrpc":"1.0","method":"node","params":["remove","1.1.1.1"],"id":1}`,
+			unmarshalled: &btcjson.NodeCmd{
+				SubCmd: btcjson.NRemove,
+				Target: "1.1.1.1",
+			},
+		},
+		{
+			name: "node",
+			newCmd: func() (interface{}, error) {
+				return btcjson.NewCmd("node", btcjson.NDisconnect, "1.1.1.1")
+			},
+			staticCmd: func() interface{} {
+				return btcjson.NewNodeCmd("disconnect", "1.1.1.1", nil)
+			},
+			marshalled: `{"jsonrpc":"1.0","method":"node","params":["disconnect","1.1.1.1"],"id":1}`,
+			unmarshalled: &btcjson.NodeCmd{
+				SubCmd: btcjson.NDisconnect,
+				Target: "1.1.1.1",
+			},
+		},
+		{
+			name: "node",
+			newCmd: func() (interface{}, error) {
+				return btcjson.NewCmd("node", btcjson.NConnect, "1.1.1.1", "perm")
+			},
+			staticCmd: func() interface{} {
+				return btcjson.NewNodeCmd("connect", "1.1.1.1", btcjson.String("perm"))
+			},
+			marshalled: `{"jsonrpc":"1.0","method":"node","params":["connect","1.1.1.1","perm"],"id":1}`,
+			unmarshalled: &btcjson.NodeCmd{
+				SubCmd:        btcjson.NConnect,
+				Target:        "1.1.1.1",
+				ConnectSubCmd: btcjson.String("perm"),
+			},
+		},
+		{
+			name: "node",
+			newCmd: func() (interface{}, error) {
+				return btcjson.NewCmd("node", btcjson.NConnect, "1.1.1.1", "temp")
+			},
+			staticCmd: func() interface{} {
+				return btcjson.NewNodeCmd("connect", "1.1.1.1", btcjson.String("temp"))
+			},
+			marshalled: `{"jsonrpc":"1.0","method":"node","params":["connect","1.1.1.1","temp"],"id":1}`,
+			unmarshalled: &btcjson.NodeCmd{
+				SubCmd:        btcjson.NConnect,
+				Target:        "1.1.1.1",
+				ConnectSubCmd: btcjson.String("temp"),
+			},
+		},
 		{
 			name: "getbestblock",
 			newCmd: func() (interface{}, error) {

diff --git a/docs/json_rpc_api.md b/docs/json_rpc_api.md
@@ -186,7 +186,7 @@ the method name for further details such as parameter and return information.
 |   |   |
 |---|---|
 |Method|addnode|
-|Parameters|1. peer (string, required) - ip address and port of the peer tooperate on<br />2. command (string, required) - `add` to add a persistent peer, `remove` to remove a persistent peer, or `onetry` to try a single connection to a peer|
+|Parameters|1. peer (string, required) - ip address and port of the peer to operate on<br />2. command (string, required) - `add` to add a persistent peer, `remove` to remove a persistent peer, or `onetry` to try a single connection to a peer|
 |Description|Attempts to add or remove a persistent peer.|
 |Returns|Nothing|
 [Return to Overview](#MethodOverview)<br />
@@ -553,6 +553,8 @@ The following is an overview of the RPC methods which are implemented by btcd, b
 |2|[getbestblock](#getbestblock)|Y|Get block height and hash of best block in the main chain.|None|
 |3|[getcurrentnet](#getcurrentnet)|Y|Get bitcoin network btcd is running on.|None|
 |4|[searchrawtransactions](#searchrawtransactions)|Y|Query for transactions related to a particular address.|None|
+|5|[node](#node)|N|Attempts to add or remove a peer. |None|
+
 
 <a name="ExtMethodDetails" />
 **6.2 Method Details**<br />
@@ -609,6 +611,18 @@ The following is an overview of the RPC methods which are implemented by btcd, b
 
 ***
 
+<a name="node"/>
+
+|   |   |
+|---|---|
+|Method|node|
+|Parameters|1. command (string, required) - `connect` to add a peer (defaults to temporary), `remove` to remove a persistent peer, or `disconnect` to remove all matching non-persistent peers <br /> 2. peer (string, required) - ip address and port, or ID of the peer to operate on<br /> 3. connection type (string, optional) - `perm` indicates the peer should be added as a permanent peer, `temp` indicates a connection should only be attempted once. |
+|Description|Attempts to add or remove a peer.|
+|Returns|Nothing|
+[Return to Overview](#MethodOverview)<br />
+
+***
+
 <a name="WSExtMethods" />
 ### 7. Websocket Extension Methods (Websocket-specific)
 

diff --git a/rpcserver.go b/rpcserver.go
@@ -155,6 +155,7 @@ var rpcHandlersBeforeInit = map[string]commandHandler{
 	"gettxout":              handleGetTxOut,
 	"getwork":               handleGetWork,
 	"help":                  handleHelp,
+	"node":                  handleNode,
 	"ping":                  handlePing,
 	"searchrawtransactions": handleSearchRawTransactions,
 	"sendrawtransaction":    handleSendRawTransaction,
@@ -369,17 +370,125 @@ func handleAddNode(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (in
 	case "onetry":
 		err = s.server.AddAddr(addr, false)
 	default:
-		err = errors.New("invalid subcommand for addnode")
+		return nil, &btcjson.RPCError{
+			Code:    btcjson.ErrRPCInvalidParameter,
+			Message: "invalid subcommand for addnode",
+		}
 	}
 
 	if err != nil {
-		return nil, internalRPCError(err.Error(), "")
+		return nil, &btcjson.RPCError{
+			Code:    btcjson.ErrRPCInvalidParameter,
+			Message: err.Error(),
+		}
 	}
 
 	// no data returned unless an error.
 	return nil, nil
 }
 
+// handleNode handles node commands.
+func handleNode(s *rpcServer, cmd interface{}, closeChan <-chan struct{}) (interface{}, error) {
+	c := cmd.(*btcjson.NodeCmd)
+
+	var addr string
+	var nodeId uint64
+	var errN, err error
+	switch c.SubCmd {
+	case "disconnect":
+		// If we have a valid uint disconnect by node id. Otherwise,
+		// attempt to disconnect by address, returning an error if a
+		// valid IP address is not supplied.
+		if nodeId, errN = strconv.ParseUint(c.Target, 10, 32); errN == nil {
+			err = s.server.DisconnectNodeById(int32(nodeId))
+		} else {
+			if _, _, errP := net.SplitHostPort(c.Target); errP == nil || net.ParseIP(c.Target) != nil {
+				addr = normalizeAddress(c.Target, activeNetParams.DefaultPort)
+				err = s.server.DisconnectNodeByAddr(addr)
+			} else {
+				return nil, &btcjson.RPCError{
+					Code:    btcjson.ErrRPCInvalidParameter,
+					Message: "invalid address or node ID",
+				}
+			}
+		}
+		if err != nil && peerExists(s.server.PeerInfo(), addr, int32(nodeId)) {
+			return nil, &btcjson.RPCError{
+				Code:    btcjson.ErrRPCMisc,
+				Message: "can't disconnect a permanent peer, use remove",
+			}
+		}
+	case "remove":
+		// If we have a valid uint disconnect by node id. Otherwise,
+		// attempt to disconnect by address, returning an error if a
+		// valid IP address is not supplied.
+		if nodeId, errN = strconv.ParseUint(c.Target, 10, 32); errN == nil {
+			err = s.server.RemoveNodeById(int32(nodeId))
+		} else {
+			if _, _, errP := net.SplitHostPort(c.Target); errP == nil || net.ParseIP(c.Target) != nil {
+				addr = normalizeAddress(c.Target, activeNetParams.DefaultPort)
+				err = s.server.RemoveNodeByAddr(addr)
+			} else {
+				return nil, &btcjson.RPCError{
+					Code:    btcjson.ErrRPCInvalidParameter,
+					Message: "invalid address or node ID",
+				}
+			}
+		}
+		if err != nil && peerExists(s.server.PeerInfo(), addr, int32(nodeId)) {
+			return nil, &btcjson.RPCError{
+				Code:    btcjson.ErrRPCMisc,
+				Message: "can't remove a temporary peer, use disconnect",
+			}
+		}
+	case "connect":
+		addr = normalizeAddress(c.Target, activeNetParams.DefaultPort)
+
+		// Default to temporary connections.
+		subCmd := "temp"
+		if c.ConnectSubCmd != nil {
+			subCmd = *c.ConnectSubCmd
+		}
+
+		switch subCmd {
+		case "perm", "temp":
+			err = s.server.ConnectNode(addr, subCmd == "perm")
+		default:
+			return nil, &btcjson.RPCError{
+				Code:    btcjson.ErrRPCInvalidParameter,
+				Message: "invalid subcommand for node connect",
+			}
+		}
+	default:
+		return nil, &btcjson.RPCError{
+			Code:    btcjson.ErrRPCInvalidParameter,
+			Message: "invalid subcommand for node",
+		}
+	}
+
+	if err != nil {
+		return nil, &btcjson.RPCError{
+			Code:    btcjson.ErrRPCInvalidParameter,
+			Message: err.Error(),
+		}
+	}
+
+	// no data returned unless an error.
+	return nil, nil
+}
+
+// peerExists determines if a certain peer is currently connected given
+// information about all currently connected peers. Peer existence is
+// determined using either a target address or node id.
+func peerExists(peerInfos []*btcjson.GetPeerInfoResult, addr string, nodeId int32) bool {
+	for _, peerInfo := range peerInfos {
+		if peerInfo.ID == nodeId || peerInfo.Addr == addr {
+			return true
+		}
+	}
+	return false
+}
+
 // messageToHex serializes a message to the wire protocol encoding using the
 // latest protocol version and returns a hex-encoded string of the result.
 func messageToHex(msg wire.Message) (string, error) {

diff --git a/rpcserverhelp.go b/rpcserverhelp.go
@@ -33,6 +33,12 @@ var helpDescsEnUS = map[string]string{
 	"addnode-addr":      "IP address and port of the peer to operate on",
 	"addnode-subcmd":    "'add' to add a persistent peer, 'remove' to remove a persistent peer, or 'onetry' to try a single connection to a peer",
 
+	// NodeCmd help.
+	"node--synopsis":     "Attempts to add or remove a peer.",
+	"node-subcmd":        "'disconnect' to remove all matching non-persistent peers, 'remove' to remove a persistent peer, or 'connect' to connect to a peer",
+	"node-target":        "Either the IP address and port of the peer to operate on, or a valid peer ID.",
+	"node-connectsubcmd": "'perm' to make the connected peer a permanent one, 'temp' to try a single connect to a peer",
+
 	// TransactionInput help.
 	"transactioninput-txid": "The hash of the input transaction",
 	"transactioninput-vout": "The specific output of the input transaction to redeem",
@@ -521,6 +527,7 @@ var rpcResultTypes = map[string][]interface{}{
 	"getrawtransaction":     []interface{}{(*string)(nil), (*btcjson.TxRawResult)(nil)},
 	"gettxout":              []interface{}{(*btcjson.GetTxOutResult)(nil)},
 	"getwork":               []interface{}{(*btcjson.GetWorkResult)(nil), (*bool)(nil)},
+	"node":                  nil,
 	"help":                  []interface{}{(*string)(nil), (*string)(nil)},
 	"ping":                  nil,
 	"searchrawtransactions": []interface{}{(*string)(nil), (*[]btcjson.TxRawResult)(nil)},